The study investigates the role of mRNA m6A demethylase OsALKBH9 in male fertility regulation in rice. OsALKBH9 knockout mutants exhibit male sterility, delayed tapetal programmed cell death (PCD), and excessive accumulation of pollen exine. Cytological and transcriptomic analyses reveal that OsALKBH9 is involved in the regulation of genes related to tapetal development and pollen exine accumulation. OsALKBH9 demethylates m6A modifications in TDR and GAMYB transcripts, affecting their stability and downstream gene expression. The findings highlight the importance of m6A demethylation in controlling rice fertility and provide insights into the molecular mechanisms underlying male sterile materials for hybrid breeding.The study investigates the role of mRNA m6A demethylase OsALKBH9 in male fertility regulation in rice. OsALKBH9 knockout mutants exhibit male sterility, delayed tapetal programmed cell death (PCD), and excessive accumulation of pollen exine. Cytological and transcriptomic analyses reveal that OsALKBH9 is involved in the regulation of genes related to tapetal development and pollen exine accumulation. OsALKBH9 demethylates m6A modifications in TDR and GAMYB transcripts, affecting their stability and downstream gene expression. The findings highlight the importance of m6A demethylation in controlling rice fertility and provide insights into the molecular mechanisms underlying male sterile materials for hybrid breeding.